See below. Aspirin is a nonsteroidal anti-inflammatory drug (nsaids), but differs from most other nsaids in the mechanism of action. Though it, and others in its group called the salicylates, have similar effects (antipyretic, anti-inflammatory, analgesic) to the other nsaids and inhibit the same enzyme cyclooxygenase, Aspirin (but not the other salicylates) does so in an irreversible manner.